300 Joule of work is done in sliding a 2 kg block up an inclined plane to a height of 10 meters. Taking value of acceleration due to gravity ‘g’ to be 10 m/s², work done against friction is

The correct answer is 100 J.

When a block is pushed up an inclined plane, the total work done by the applied force goes into two parts:

1. Work done against gravity (to raise the block to height h)
2. Work done against friction (to overcome the frictional force along the surface)

This can be written as:

W_{\mathrm{total}}=W_{\mathrm{gravity}}+W_{\mathrm{friction}}

Step 1: Identify the given values.

Total work done, W_{\mathrm{total}}=300\text{J}
Mass of block, m=2\text{kg}
Height gained, h=10\text{m}
Acceleration due to gravity, g=10\text{m/s²}

Step 2: Calculate the work done against gravity.

The work done against gravity equals the gain in gravitational potential energy:

W_{\mathrm{gravity}}=mgh=2\times 10\times 10=200\text{J}

Step 3: Calculate the work done against friction.

Using the energy balance equation:

W_{\mathrm{friction}}=W_{\mathrm{total}}-W_{\mathrm{gravity}}

W_{\mathrm{friction}}=300-200=100\text{J}

Conclusion: Out of the 300 J of total work done, 200 J was used to raise the block against gravity, and the remaining 100 J was spent overcoming friction along the inclined surface.